A New Circuit for Pulse Shape Discrimination

A new electronic circuit has been developed for discriminating between pulses induced by neutrons and gammas in organic detectors. Both stilbene and NE 213 may be used as detectors with no change in the pulse shape discriminator circuit. The circuit is contained in an AEC module of standard dimensions and is designed to be compatible with modular counting systems. Pulse shape discrimination is obtained by comparing the light emitted during the early part of the pulse with the light emitted in the first 1 ¿ sec interval. New electronic techniques employed in the comparison circuits make it possible to achieve an electronic dead time of less than L5 ¿ sec. Two logic signals are provided to identify neutron and gamma pulses so that neutron and gamma spectroscopy may be simultaneously performed. The time at which these logic signals appear is defined by the application of a.marker to the circuit. The circuit has been used over a neutran energy range of 1 - 15 MeV and applied to the measurement of energy spectra from neutron sources and to photoneutron spectroscopy.